10 Jul 2024

Historic Landscape Inventory for Zachary Taylor National Cemetery, Louisville, Kentucky

Abstract: This project was undertaken to provide the US Department of Veterans Affairs, National Cemetery Administration, with a cultural landscape inventory of Zachary Taylor National Cemetery via funding from the St Louis Mandatory Center of Expertise (MCX) for the Curation and Management of Archaeological Collections (CMAC). The 16-acre cemetery, listed on the National Register of Historic Places in 1983, is found in Louisville, Kentucky, and contains more than 11,400 burials. The US Army Engineer Research and Development Center-Construction Engineering Research Laboratory (ERDC-CERL) was tasked with inventorying and assessing the cultural landscape at Zachary Taylor National Cemetery through the creation of a landscape development context, a description of current conditions, and an analysis of changes to the cultural landscape over time. All landscape features were included in the survey as federal policy on national cemeteries requires that all national cemetery landscape features be considered contributing elements, regardless of age. The historic landscape elements of the cemetery, like the original overarching Beaux-Arts plan and circulation, cannot be restored due to the current number of burials. However, some elements can be reemphasized by historic landscape management planning, such as the restoration of the portions of the allée of pin oak (Quercus palustris) trees.

10 Jul 2024

Historic Landscape Inventory for Mare Island Naval Cemetery, California

Abstract: This project was undertaken to provide the US Department of Veterans Affairs (VA), National Cemetery Administration (NCA), with a cultural land-scape inventory of Mare Island Naval Cemetery. The approximately 2.5-acre cemetery is located in Vallejo, California, and contains more than 900 burials. Mare Island Naval Cemetery is part of the Mare Island Naval Shipyard historic district, which was listed concurrently on the National Register of Historic Places and as a National Historic Landmark in 1975. The NCA tasked the US Army Engineer Research and Development Center-Construction Engineering Research Laboratory (ERDC-CERL) with inventorying and assessing the cultural landscape at Mare Island Naval Cemetery through the creation of a landscape development context, a description of current conditions, and an analysis of changes to the cultural landscape over time. All landscape features were included in the inventory as NCA requested ERDC-CERL to follow federal policy on national cemeteries that requires that all national cemetery landscape features be considered contributing elements, regardless of age.

10 Jul 2024

A Study of Phased-Array Ultrasonic Testing (PAUT) for Detecting, Sizing, and Characterizing Flaws in the Welds of Existing Hydraulic Steel Structures (HSS)

Abstract: Hydraulic steel structures (HSS) are components of navigation, flood control, and hydropower projects that control or regulate the flow of water. Damage accumulates in HSS as they are operated over time, and they must be inspected periodically. This is often accomplished using nondestructive testing (NDT) techniques. If damage is detected, the structure’s fitness for continued service must be evaluated, which requires information on the location and size of discontinuities. This information can be obtained using ultrasonic testing (UT) techniques. However, there is limited information on the reliability of UT techniques with respect to detecting, sizing, and characterizing flaws in HSS. This study addresses this gap. Round-robin experiments were carried out using phased-array ultrasonic testing (PAUT) to scan weld specimens representing a variety of HSS geometries. The results of the round-robin experiments were analyzed to estimate the probability of detection (POD) and to assess the influence of factors potentially affecting POD. Uncertainty in estimates of flaw length and height were described, and partial safety factors were derived for use in fitness-for-service analyses. These results demonstrate the importance of the technician as a factor influencing the reliability of NDT techniques applied to HSS.

26 Jun 2024

Flowering Rush Control in Hydrodynamic Systems: Part 2: Field Demonstrations for Chemical Control of Flowering Rush

Abstract: A series of 10 water-exchange studies were conducted from 2019 to 2021 at two sites, Clover Island and Osprey Point, within the McNary Pool of the Columbia River on the Oregon-Washington border. Six of the studies incorporated a barrier curtain or bubble curtain, whereas the other four studies did not include any device to mitigate water exchange. Once annually, diquat aquatic herbicide was applied concurrently with rhodamine water tracing (RWT) dye at the Osprey Point site (2019–2021) to control flowering rush. An additional plot, Clover Island Reference, served as the nontreated control to the Osprey Point treatment plot. Pre- and posttreatment vegetation surveys were conducted in 2019, 2020, and 2021 to determine flowering rush control, treatment impacts to water quality, and nontarget species response. This study sought to (1) document the use of barrier curtains and bubble curtains as potential methods for reducing water exchange and increasing herbicide concentration exposure times within potential flowering rush treatment areas, (2) evaluate bulk water exchange and selective control of flowering rush under varying reservoir operations, and (3) use the results from these studies to provide guidance for managing submersed flowering rush infestations on the McNary Pool, Columbia River, and similar run-of-the-river impoundments.

25 Jun 2024

US Army Corps of Engineers (USACE) Wave Information Study: 2021 Annual Update

Purpose: This Coastal and Hydraulics Engineering Technical Note (CHETN) describes the 2021 Wave Information Study (WIS) annual update. Within this CHETN, we summarize the WIS input data, explain the model technologies, detail the quality control / quality assurance (QA/QC), and provide statistical evaluation of the 2021 WIS estimates as compared to in situ buoys and remotely sensed satellite altimeter data.

25 Jun 2024

The Effect of Increasing the Antenna Height on Radio Signal Reception at Tom Bevill Lock and Dam: LOMA-AIS Data Case Study

Abstract: This Coastal and Hydraulics Engineering Technical Note (CHETN) presents the effects on the reception of radio signals due to increasing the antenna height at Tom Bevill Lock and Dam (L&D) in Pickensville, Alabama. The signals are received Automatic Identification System (AIS) broadcasts from commercial vessels operating along the Tennessee-Tombigbee Waterway. These AIS broadcasts are received by the Lock Operations Management Application (LOMA) radio equipment at Tom Bevill L&D.

21 Jun 2024

Iron Oxidation–Reduction Processes in Warming Permafrost Soils and Surface Waters Expose a Seasonally Rusting Arctic Watershed

Abstract: Landscape-scale changes from climate change in the Arctic affect the soil thermal regime and impact the depth to permafrost in vulnerable tundra watersheds. When top-down thaw of permafrost occurs, oxygen and porewaters infiltrate deeper in the soil column exposing fresh, previously frozen material and altering redox conditions. A gap remains in understanding how redox stratifications in thawing permafrost impact the geochemistry of watersheds in response to climate change and how investigations into redox may be scaled by coupling extensive geophysical mapping techniques. In this study, we collected soils and soil porewaters from three soil pits and surface water samples from an Arctic watershed on the North Slope of Alaska and analyzed for trace metals iron (Fe) and manganese (Mn) and Fe oxidation state using bulk and microscale techniques. We also used geophysical mapping and soil thermistors to measure active layer depths across the watershed to relate accelerating permafrost thaw to watershed geochemistry. Overall, evidence showed that Fe and Mn could be useful as geochemical indicators of permafrost thaw and release of Fe(II) from thawing permafrost and further oxidation to Fe(III) could translate to a higher degree of seasonal rusting coinciding with the warming and thawing of near surface-permafrost.

21 Jun 2024

Multiscale Observation Product (MOP) for Temporal Flood Inundation Mapping of the 2015 Dallas Texas Flood

Abstract: This paper presents a new data fusion multiscale observation product (MOP) for flood emergencies. The MOP was created by integrating multiple sources of contributed open-source data with traditional spaceborne remote sensing imagery to provide a sequence of high spatial and temporal resolution flood inundation maps. The study focuses on the 2015 Memorial Day floods that caused up to US$61 million of damage. The Hydraulic Engineering Center River Analysis System (HEC-RAS) model was used to simulate water surfaces for the northern part of the Trinity River in Dallas, using reservoir surcharge releases and topographic data provided by the US Army Corps of Engineers. A measure of fit assessment is performed on the MOP flood maps with the HEC-RAS simulated flood inundation output to quantify spatial differences. Estimating possible flood inundation using individual datasets that vary spatially and temporally allow an understanding of how much each observational dataset contributes to the overall water estimation. Results show that water surfaces estimated by MOP are comparable with the simulated output for the duration of the flood event. Additionally, contributed data, such as Civil Air Patrol, although they may be geographically sparse, become an important data source when fused with other observation data.

21 Jun 2024

Observations of Beach Change and Runup, and the Performance of Empirical Runup Parameterizations during Large Storm Events

Abstract: Timeseries observations of beach elevation change and wave runup from a tower-mounted stationary lidar assess the skill of 2% runup exceedance (𝑅2%) estimates during four storm events at Duck, NC. The runup parameterization requires the foreshore beach slope, which generally unknown during high energy events. Pre-storm estimates are often used as a proxy. 𝑅2% hindcasts use the observed time-varying beach slope and a static pre-storm beach profile, yielding an 𝑅2% skill of 0.57. The skill drops to −1.0 using seasonal mean beach slopes and reduces after the peak of two storms with the appearance of beach cusps in the swash zone morphology. One storm’s runup is underpredicted by up to 1.0 m at high tides following the storm peak when cusps are present Additional pre- and post-storm mobile lidar surveys for one storm confirm ubiquitous small-scale beach cusps along 8 km of the local shoreline. The results suggest skillful runup estimates are often attainable given the availability of beach information before a storm. The parameterization errors increase when beach cusps develop, highlighting the need to extend standard one-dimensional runup parameterizations to account for two-dimensional effects.

20 Jun 2024

Spatial Variations in Vegetation Fires and Emissions in South and Southeast Asia during COVID-19 and Pre-pandemic

Abstract: Vegetation fires are common in South/Southeast Asian (SA/SEA) countries. However, few studies focused on vegetation fires and the changes during COVID compared to pre pandemic. This study fills an information gap and reports total fire incidences, total burnt area, type of vegetation burnt, and total particulate matter emission variations. Results from the short term 2020 COVID versus 2019 non COVID year showed a decline in fire counts varying from -2.88 to 79.43%. The exceptions in South Asia include Afghanistan and Sri Lanka, and Cambodia and Myanmar in Southeast Asia. The burnt area decline for 2020 compared to 2019 varied from -0.8% to 92% for South/Southeast Asian countries, with most burning in agricultural landscapes than forests. Several patches in S/SEA showed a decrease in fires for the 2020 pandemic year compared to long term 2012–2020 pre pandemic record, with Z scores greater or less than two denoting statistical significance. However, on a country scale, the results were not statistically significant in both S/SEA, with Z scores ranging from -0.24 to -1, although most countries experienced a decrease in fire counts. The study highlights variations in fires and emissions useful for fire management and mitigation.